A variety of fillers is used in elastomeric materials both for the purpose of increasing bulk as well as reinforcement. Carbon black is widely used as a reinforcing filler, and improves the tensile strength of a wide variety of elastomers. However, fluoroelastomers have presented special problems in this regard, since the reinforcing materials used for elastomers in general have little or no beneficial effect when used with fluorinated elastomers. Accordingly, fillers with coupling agents in conjunction with carbonaceous fillers have been suggested for certain peroxide curable, hydrogen containing, fluoroelastomers in Martin U.S. Pat. No. 4,251,432. However, these coated carbonaceous fillers are ineffective when used with non-hydrogen containing perfluoroelastomers of the type prepared from tetrafluoroethylene and perfluoromethyl perfluorovinyl ether. Such elastomeric materials have extraordinary resistance to corrosive high temperature environments, but typically exhibit a low tensile strength and elongation at break which limits their range of applicability. These low tensile properties require the use of separate backing elements in conjunction with parts made from such polymers. A need therefore exists for fillers which can be effectively used to reinforce perfluoroelastomers and particularly to improve the tensile properties of these materials.